<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<style>
    .circle, .halfCircle {
        width: 200px;
        height: 200px;
        background-color: lime;
        border-radius: 50%;
    }
    .circle {

    }
    .halfCircle {
       background-color: aqua;
        overflow: hidden;
    }
    .ju {
        background-color: white;
        height: 50%;
    }
</style>
<body>
<div class="circle"></div>
<div class="halfCircle">
    <div class="ju"></div>
</div>

</body>
</html>
